We are studying the binding of pyridoxal 5' -phosphate to variety of enzymes, including glutamate decarboxylase, aspartate aminotransferase, D-serine dehydratase, and dopa decarboxylase. We study coenzyme binding by kinetic methods, by titration methods, by nuclear magnetic resonance, and by spectrophotometric methods. We synthesize and study analogs of pyridoxal 5' phosphate with these same enzymes. We study the roles of various amino acids in the coenzyme binding process. We attempt to determine the role of coenzyme binding in various important metabolic process, particularly processes in the nervous system.